Scientists have moved closer to understanding why cancer cells can be so resilient, even when faced with the onslaught of nearly toxic drug cocktails, radiation, and even our own immune systems. A new research report appearing ...

Cancer patients with limited brain metastases (one to four tumors) who are 50 years old and younger should receive stereotactic radiosurgery (SRS) without whole brain radiation therapy (WBRT), according to a study available ...

Mar 02, 2015

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Metastasis, or metastatic disease (sometimes abbreviated mets), is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research. The word metastasis means "displacement" in Greek, from μετά, meta, "next", and στάσις, stasis, "placement". The plural is metastases.

Cancer occurs after a single cell in a tissue is progressively genetically damaged to produce a cancer stem cell possessing a malignant phenotype. These cancer stem cells are able to undergo uncontrolled abnormal mitosis, which serves to increase the total number of cancer cells at that location. When the area of cancer cells at the originating site becomes clinically detectable, it is called a primary tumor. Some cancer cells also acquire the ability to penetrate and infiltrate surrounding normal tissues in the local area, forming a new tumor. The newly formed "daughter" tumor in the adjacent site within the tissue is called a local metastasis.

Some cancer cells acquire the ability to penetrate the walls of lymphatic and/or blood vessels, after which they are able to circulate through the bloodstream (circulating tumor cells) to other sites and tissues in the body. This process is known (respectively) as lymphatic or hematogeneous spread.

After the tumor cells come to rest at another site, they re-penetrate through the vessel or walls, continue to multiply, and eventually another clinically detectable tumor is formed. This new tumor is known as a metastatic (or secondary) tumor. Metastasis is one of three hallmarks of malignancy (contrast benign tumors). Most tumors and other neoplasms can metastasize, although in varying degrees (e.g. basal cell carcinoma) rarely metastasize.

When tumor cells metastasize, the new tumor is called a secondary or metastatic tumor, and its cells are like those in the original tumor. This means, for example, that, if breast cancer metastasizes to the lungs, the secondary tumor is made up of abnormal breast cells, not of abnormal lung cells. The tumor in the lung is then called metastatic breast cancer, not lung cancer.

Studies indicate that the majority of people with mood and anxiety disorders who receive the most commonly prescribed class of antidepressant medications, Selective Serotonin Reuptake Inhibitors or SSRI's, are not helped ...

Young women with ADHD who have been exposed to abuse, neglect or other traumas in childhood and adolescence are at greater risk for self-injury, eating disorders and suicide than those with ADHD who were ...

Attendance at schools exposed to high levels of traffic-related air pollution is linked to slower cognitive development among 7-10-year-old children in Barcelona, according to a study published by Jordi Sunyer ...

Tumor recurrence following a period of remission is the main cause of death in cancer. The ability of cancer cells to remain dormant during and following therapy, only to be reactivated at a later time, frequently ...

Doctors write millions of prescriptions a year for drugs to calm the behavior of people with Alzheimer's disease and other types of dementia. But non-drug approaches actually work better, and carry far fewer ...

Two hearts, said Keats, can beat as one; but a study led by Weizmann Institute scientists in collaboration with researchers from the University of Pennsylvania shows that sometimes a single heart muscle cell ...

Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a study published by Cell Press March 3rd ...

Gastric bypass and similar stomach-shrinking surgeries are a popular option for obese patients looking to lose weight or treat type 2 diabetes. While the surgeries have been linked to a decreased risk in many types of cancers, ...